Dugald River case study — the importance of understanding your orebody and designing your mine for maximum value

Abstract

The Dugald River Zn-Pb-Ag deposit was first discovered pre-1880, and is regarded as one of the largest and highest-grade undeveloped deposits of zinc in the world with a mineral resource of 55 Mt at 13.4% zinc, 2.1% lead and 36 g/t silver. It was largely neglected until the 1950s, when systematic exploration was conducted; however, due to low base metal prices and the discovery and development of nearby deposits, the orebody remained undeveloped.Exploration decline development started in February 2012, providing early access to the orebody. Towards the end of 2012, exposure of the geological conditions in oredrive development and from underground diamond drilling highlighted a more complex and challenging mining environment than understood from the feasibility study.It is the purpose of this paper to explain in some detail the evolution in the technical understanding of the Dugald River deposit following its acquisition by MMG Limited. The advancement of technical knowledge not only led to a reduction in project risk and uncertainty, but also had significant impact on mine design and the project development plan.The importance of understanding and continually responding to the unique characteristics of an ore body and designing your project to maximise long-term value has been reinforced at Dugald River.